Ali Alatas, who has died aged 76, was one of Indonesia's most widely respected foreign ministers. A charismatic and urbane man - known affectionately as "Pak Ali" - he was tipped to become the United Nations secretary general in the 1990s. But his boss, the Indonesian dictator Suharto, is said to have opposed the move, fearing it would shine a spotlight on the country's questionable human rights record in East Timor.

Alatas was born in Jakarta. He graduated from the Academy for the Indonesian Foreign Service in 1954 and the University of Indonesia's law faculty two years later. A career diplomat, he was stationed in various embassies of Indonesia, including those in Bangkok and Washington DC, and he twice served as Indonesia's ambassador to the UN, in Geneva from 1975 to 1978 and in New York between 1982 and 1988. That year, in the final decade of Suharto's 32-year reign, he became Indonesia's foreign minister, serving another year under the dictator's successor, BJ Habibie.

Successive Indonesian presidents, including the current incumbent, Susilo Bambang Yudhoyono, valued his long experience and unflappable nature. Each ensured that he stayed around as a foreign adviser. Most recently, he was instrumental in seeing that the 10-member Association of South East Asian Nations (Asean) enshrined the values of human rights and democracy in a charter that came into force this week. He was also a board member of the Brussels-based International Crisis Group. Alatas was in recent years a UN special envoy tasked with drafting a report on security, development and human rights.

But his soaring diplomatic career was always tarnished by Indonesia's abuses in East Timor, after it invaded and occupied the former Portuguese colony once it had achieved independence in 1975. Alatas's diplomatic skills were tested to the full by the Suharto regime's often brutal repression in East Timor, and elsewhere. Alatas admitted that the 1991 massacre of pro-independence demonstrators by Indonesian troops at the Santa Cruz cemetery in the capital, Dili, in which hundreds of civilians died, was a "turning point". Even nations that had supported Indonesia were "shocked" by the carnage, which was captured on film by Max Stahl, a British journalist and documentary maker. It led to Indonesia's isolation by the west for years.

International outrage over the deaths may have cost Alatas the top UN job, for which he was in the running in the late 1990s. Suharto reportedly vetoed his candidacy as he believed the role would have highlighted such abuses.

After his long stint as foreign minister under Suharto, who was swept from power in May 1998 by mass street protests, he served just one year as Habibie's senior diplomat. But it was an uncomfortable time; Habibie failed to consult him, notably on the decision to stage a referendum on East Timor that ended Jakarta's 24-year occupation in 1999. The mayhem that ensued, when more than 1,000 East Timorese died as Jakarta-backed militias went on the rampage, were a further stain on Alatas.

In 2001, Alatas compiled a book, A Voice for a Just Peace that contained a selection of his speeches with some commentary, though only one passage on East Timor was included. It also highlighted Indonesia's desire for economic and social justice on a global scale, demanding an end to nuclear testing and the reform of the UN to end superpower domination. Indonesia's wish to discuss "moral" alternatives on the world stage was, however, blighted by East Timor.

Yet five years later, Alatas' ground-breaking work, The Pebble in the Shoe: The Diplomatic Struggle for East Timor, helped stir a wider debate about the occupation and forced Indonesia to start to re-examine its rule there.

Some successes helped to underpin Alatas's reputation as an international statesman. His greatest triumph was his work with the Cambodian prime minister Hun Sen, who had been appointed by the invading Vietnamese in 1978; Alatas brokered the historic 1991 peace settlement at the Paris International Conference to end the war with the Khmer Rouge, though he had to share some of the glory with France, which joined the negotiations late in the day. Less successfully he also battled hard with Asean neighbour Burma for the release of opposition leader, Aung San Suu Kyi, who has spent 13 of the last 19 years under house arrest.